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Sea Turtles, Sound, and Sun Block

Hello, fellow STEM enthusiasts! My name is Emily Waddell and I’m working with Dr. Wendy Piniak, from the Environmental Studies Department, this summer. Dr. Piniak and I are spending eight full weeks off of Gettysburg’s campus conducting research in Bahia de Los Angeles, Baja California, Mexico and at the Duke University Marine Lab (DUML) in Beaufort, NC.

Me and Dr. Piniak

Collaborations in Bahia de Los Angeles

When Dr. Piniak first explained the Bahia trip to me, I was beyond excited and could not contain my enthusiasm to get to travel to a new country, conduct field research with her, and meet other scientists and students from around the country. Our field site host is Ocean Discovery Institute (ODI), an impressive non-profit organization dedicated to helping and empowering underserved youth from the San Diego area through science and leadership opportunities. They recently won the 2016 CNN Hero Award! Even with Dr. Piniak’s numerous warnings of lack of down-time, draining heat, and early mornings, I was eager to hop on the plane mid-June. We flew to San Diego, CA then drove 12 hours south to Bahia de Los Angeles, a small coastal town on the west side of the Gulf of California.

Dr. Piniak’s lab focuses on sensory ecology which is the study of how animals receive and respond to sensory cues in their environment. Our specific focus is on how sea turtles and other marine animals respond to acoustic cues. While in Baja we worked with a collaborative team made up of Ocean Discovery Institute students and staff, NOAA Fisheries scientists, engineers from FlyWire Cameras, and local fishermen to study how we can use sound to prevent sea turtles from becoming fisheries bycatch (any organism that is unintentionally caught in fishing gear), which can cause injury or death to the sea turtle. Reducing sea turtle bycatch is crucial for the success of sea turtle protection and conservation because fishing gear/nets are a large threat to sea turtle populations globally. Our team’s goal is to develop sensory-based bycatch reduction tools that will reduce sea turtle bycatch but maintain target catch. Dr. Piniak’s previous research shows that sea turtles can hear low frequency sounds (<2000 Hz), and previous research in Bahia has shown that putting low-frequency sound on nets reduces sea turtle interactions with nets. With the help of FlyWire this year, we tested new underwater Acoustic Deterrent Devices (ADDs), which emit low frequency sounds. Our hope is that when these ADDs are attached to fishing nets, the sea turtles will change their behavior and move away from the net, preventing sea turtles from becoming bycatch.

The new underwater ADD

ADDs in Action

On my second day in Bahia, we went into the field with these new ADDs. Dr. Piniak and I set out to test the impact of ADDs on sea turtle catch with Jorge, an Ocean Discovery Institute Research Fellow, Tony, a FlyWire technician/representative, Joel, the Director of Research at Ocean Discovery Institute, and Ricardo and Guero, two local fishermen who are part of a local sea turtle monitoring group (Grupo Marino). We set a pair of 90 meter gillnets, an experimental net and a control net, at La Gringa Bay. We attached five ADDs on the experimental net placed 20 meters apart. Each ADD played tones between 200 and 500 Hz (the best hearing range of sea turtles). On the control net we attached flower pots that resembled the shape and size of the ADDs but did not emit any sound. We then checked the nets every 75 minutes to see if any sea turtles were caught. If a sea turtle was caught, we brought the turtle on board the boat and recorded the species, time it was found, and which net it was caught in. As part of the local sea turtle monitoring program, we also collected size measurements (curved carapace length and width), made note of any previous tags, and if no tags were present, tagged the turtles using iconel flipper tags. I got to tag and release my first green sea turtle that day. It was absolutely incredible! We ended up catching two green sea turtles in the experimental net and one in the control net.

A green sea turtle (una tortuga)

Over the next two and a half weeks, we went out on two more turtle ADD days, setting nets at Punta Arena and Guadalupe. Both days lacked turtles, but were great experiences and opportunities for me. On these subsequent turtle ADD days, I got to meet Dr. John Wang, a fisheries ecologist, who works for NOAA, Jacob Isaac-Lowry and Sarah Alessi, the founders of FlyWire, and Christina Fahy, a fishery biologist from the NOAA Fisheries. I received lots of graduate school advice from them, learned about their careers, and got to know them on a personal level. Turns out Dr. Wang did similar research in undergrad as I did last summer at DUML (how fiddler crab megalopae respond to adult conspecific chemical cues) and Sarah is from the same hometown that my mother went to college in and has done work in Panama, where I studied abroad last fall.

Left to right: Jacob, Tony (attaching an ADD to the experimental net), and Christina

Team Bycatch

This summer was Dr. Piniak’s fourth year collaborating with this team and the third year she has brought a student from Gettysburg to Bahia with her. I’m so privileged to have worked with such a wonderful professor and team. The people definitely made the experience for me. During our second week, we were joined by nineteen high school students, Ocean Discovery Institute’s Ocean Leaders. Each student was a member of one of three research teams: Team Bycatch, Team Spatial Subsidy, and Team Photobiology.

Two Ocean Discovery Institute students and Dr. Piniak

Our group, Team Bycatch, has two research projects going on simultaneously this summer. They want to see if ADDs affect not only sea turtle catch rates, but also the local target fish catch. It would be great if the ADDs decrease sea turtle bycatch; however, how useful would they be to local fishermen if their target catch (ex. halibut, trigger fish, etc.) can also hear the ADDs and swim away from their nets? Therefore, it’s important to also examine how ADDs affect target catch. To examine fish catch we attach the ADDs to nets fished by local fishermen, mimicking the pair of control and experimental nets we used to observe turtle catch. We set nets in the morning and when we pulled nets in the afternoon, we recorded fish species caught in each net and these catches are compared to see if the ADDs alter the target catch.

Team Bycatch is also investigating if electronic monitoring (EM) is a better, more cost effective, and accurate alternative to having an onboard observer record catch data. Two gillnets are set every evening around 19:00 and then pulled the following morning. Two students and a fisherman haul in the net, recording every species caught in the net, the sex of the fish, its state (if it is alive, dead, or injured), if there are signs of depredation, its value (if the fish is a target species to be sold for money, kept as bait or food, is bycatch (incidental), or would normally be kept but has to be thrown back because of the catch restriction (veda)), and measure it. Meanwhile, a camera, designed by FlyWire, is recording the entire time and set right above where the net is being pulled in, so that it can capture the entire view and species brought up. The students then enter their onboard data into Excel and then watch a video from the boat they were not on and record any fish they see. The onboard list is then compared to the list created after scoring (watching) each video to see how effective and accurate EM can be.

One of my favorite parts about Bahia was working and bonding with the students. They were all so eager to learn and would dive right into the research. However, I also got to bond with the students outside of a scientific atmosphere doing Zumba with them and playing soccer in town. It was so much fun and all the students called me “Speedy Gonzalez.”

I can also check “swim with a whale shark” off my bucket list. At the end of my first week in Bahia, after hours of calibrating the ADDs (making sure they were playing the sound/frequency they were supposed to at the correct volume), Dr. Piniak, Tony, Ricardo, and I went to the whale shark zone and within minutes of boating along, Ricardo spotted one. I was so excited that I grabbed my snorkel and camera, and just jumped in (not even bothering to take off my shirt and shorts). Swimming next to such an elegant creature was breathtaking. It was just me and this gentle giant swimming next to each other for a couple minutes.

A whale shark!

Every night we slept on cots under the stars and right next to the water. Because we were in such a remote area under a cloudless sky, the stars were so bright and a shooting star could be seen each night. And every morning, I was woken up by the rising sun at 5:30 am. I’ve never been a morning person, but the beautiful sunrises made each morning worth getting up early.

The view from my cot every morning

I want to give a huge thank you to Dr. Piniak for letting me join her research team this summer and bringing me down to Bahia and all the scientists and ODI students and staff I met for making Bahia a memorable, fun, exciting experience!

Team Bycatch

Now, Dr. Piniak and I are at the DUML, where Dr. Piniak is teaching a sea turtle biology and conservation course and I am working on my honors thesis with Dr. Piniak and Drs. Kathy Reinsel and Jim Welch from Wittenberg University (and my REU advisors from last year). Stay tuned for a DUML post!

*All research described in this post was conducted with appropriate Mexican research permits and Gettysburg College IACUC protocols.